The government has given the go-ahead for a firm to resume the controversial technique known as fracking to exploit gas in Lancashire.
The company, Cuadrilla, was stopped from fracking after two tremors near Blackpool.
Conditions have been imposed to minimise the risk of seismic activity.
In fracking, a mixture of water, sand and some chemicals is pumped into a well under high pressure to force the gas from the rock.
The Energy Secretary Ed Davey said shale gas was a promising new potential energy resource for the UK. It might contribute significantly to energy security and substitute for imports which are increasing as North Sea gas is decreasing.
But he warned against over-excitement: “We are still in the very early stages of shale gas exploration in the UK and it is likely to develop slowly.
“It is essential that its development should not come at the expense of local communities or the environment. Fracking must be safe and the public must be confident that it is safe.”
He said the government had uncovered management weaknesses in Cuadrilla following the minor earthquakes. These had been put right, he said.
He said impacts on water and local air pollution were already covered by the UK’s existing “stringent” rules on oil and gas.
Mr Davey said the advent of shale gas would not weaken the UK’s legally binding targets to cut greenhouse gas emissions. He announced a study from the Department for Energy and Climate Change (DECC) chief scientist David McKay on the impact of shale gas on climate change.
But he asked: “Is it not better that we produce gas in this country than gas shipped half way across the world?” He said his view was that, overall, greenhouse gases from shale gas in the UK might only be slightly greater than importing gas exploited in the conventional way.
In the US, exploitation of shale gas boom has sent energy prices tumbling, and the Prime Minister has expressed hopes that the UK can enjoy a similar boom.
But government advisers warn today that shale gas may be unlikely to bring down energy prices much in Britain.
In fact, the Committee on Climate Change warns that relying heavily on gas for future electricity supplies would leave households vulnerable to higher bills in the long run as the price of gas on the international market is volatile.
The UK won’t benefit from substantially lower prices unless the rest of Europe decides to back shale gas too, as Europe has a gas grid that allows gas to be traded to the highest bidder.
The CCC has examined the potential impact on bills of different energy systems and predicts that subsidies to renewables and nuclear would put about £100 on household bills by 2020, but that by 2050 a gas-based electricity system might cost people as much as £600 extra.